Details

Description:
With the recent upgrade to Gnome 3 all the old instructions for using xmonad as the WM in Gnome 3 stopped working. It is possible to achieve this, when running Gnome 3 in fallback mode, but it requires a few extra files for gdm and gnome-session. Something like this does it:

The xmonad package already ships with a .desktop in /etc/X11/sessions, but it's not one that makes use of gnome-session. Also, GDM doesn't seem to pick up .desktop files in that location, they need to be in /usr/share/xsessions.

I'm assuming that a .session file in the user's home dir will take precedence over one in /usr/share/gnome-session/sessions/. However, having a .desktop that allows a user to choose a specific session in GDM, without having a system-wide default session file, seems to be a bad solution.